Residents of homes having rural mailboxes or living in apartments or condominiums where mail is not delivered to the door must physically check the mailbox for the presence of mail. This can be inconvenient and time consuming when the mailbox is not close by, especially for those of limited mobility. Inconvenience and time consumption is significantly increased when it becomes necessary to retrieve, promptly after delivery, important or valuable mail in order to meet time demands or prevent theft.
A number of methods have been developed for notifying a remote resident when mail has been delivered. One system utilizes a light bulb located on the mailbox being lit when the mailbox door has been opened and remains lit after the door has been closed, until a circuit controlling the energization of the light bulb is reset by the resident. One disadvantage of this system is that it requires the mailbox to be viewable by the resident. Another disadvantage is that some systems of this type route current through underground wires to the mailbox to supply power to the light bulb and related circuits, thus increasing the cost and effort required to install and use the system. A further disadvantage of the outside light is it visually indicates to the public that there is mail in the mailbox and that no one may be at home to pick up the mail, thus enhancing the possibility of theft of mail and home burglary.
Another method involves the simple placement of a light-detecting electric cell (e.g., a photocell) inside a mailbox that activates an alarm circuit inside the home when the mailbox door is opened. This method has the disadvantage of requiring underground wires to connect the photocell to the alarm circuit. A further disadvantage is that the alarm circuit is activated whenever the mailbox is opened in the presence of light regardless of whether mail has actually been placed inside the mailbox.
An additional previously proposed mail reception indicating device includes a transmitter located inside the mailbox that transmits a signal to a receiver located in the home when mail is delivered. See U.S. Pat. No. 4,520,350. For this device to properly function, the mail carrier must raise or lower a flag on the outside of the mailbox in sequence with the opening and closing of the mailbox door. The sequence of operation is determined by whether mail is being picked up, delivered, not delivered, or a combination thereof. The complexity of the device as well as the cooperation required of a mail carrier renders it cumbersome and impractical.